On my 89 Buick lesabre, I took it to my mechanic,he changed the fuel pump, filter, crank position sensor, cam sensor, ignition module, coil, MAF sensor & housing, plugs, harmonic balancer injectors and my car still not running right. When I crank it up it idles fine but when I rev it,it sputters. He tells me he don't know what's causing it to do that but he's a mechanic. Tired of guessing games need someone who KNOWS what's the problem is & fix it. Please help if you can. They have had my car for two weeks now & still don't know what's wrong with it. I'm very upset right about now.
My car has 275000 miles.
My car has an automatic transmission.
Hi there. It seems that your issue is the fuel pressure regulator has failed. The fuel pressure regulator is designed to adjust the fuel pressure to the injectors after the fuel pump pushes the fuel to the rail under max pressure. If the fuel pressure regulator is stuck, then the fuel pressure on the rail could be low and cause an interruption to the engine performance when the engine is throttled. This will cause a lean condition on the emissions and a misfire if the pressure is too low. If you need further assistance with your engine sputtering, then seek out a professional, such as one from Your Mechanic, to help you.